Based on the relationship between braking performance of permanent magnet type eddy current retarder and structure parameters, the method of uniform design and regression analysis were applied to sensitivity analysis on influence factors for braking performance of permanent magnet type eddy current retarder. The regressive models of braking torque were established concerning inside radius of rotor, circumferential length of permanent magnet, width of air-gap, axial width of rotor influenced and height of permanent magnet, the influences of structure parameters and it’s interaction of permanent magnet type eddy current retarder on braking performance were studied systematically. Based on the result of uniform experimental design and sensitivity analysis, structure parameters were optimized by means of whole-arrangement method. The conclusion can be used in the option design, enhance braking torque and improved braking performance of permanent magnet type eddy current retarder. 